The Netherlands Cancer Institute's Bas van Steensel leads a team tracking nuclear lamina interactions with the genome in individual human cells for a study published in Cell. The researchers came up with a system in which adenine bases became methylated when they come in contact with lamin proteins that line the inner nuclear envelope. With this so-called 'molecular contact memory' method, investigators followed nuclear lamina-genome interactions in human fibrosarcoma cell lines, getting a look at the lamina-associated genome domains making contact with the nuclear lamina at different points of the cell cycle and in relation to histone methylation profiles. "Contact of individual [lamina-associated domains] with the [nuclear lamina] is linked to transcriptional repression and [histone] H3K9 dimethylation in single cells," they found, noting that this process is mediated, in part, by an H3K9 methyltransferase enzyme.
In Cell's annual special review issue, researchers tackle topics pertaining to the organization, dynamics, and function of the nucleus. This look at the genomic DNA-containing organelle includes several reviews focused on the genome — from chromosomal organization and genome stability to epigenetics and transcriptional regulation. In the same issue, a primer article considers the criteria used to define chromothripsis events in cancer genomes and the National Cancer Institute's Tom Misteli muses on the nuclear environment's role in genome function in his essay on the cell biology of genomes.
Researchers based in Japan, the US, and Austria report on findings from an influenza study suggesting that the influenza A virus may be susceptible to a lipid mediator known as protectin D1, or PD1. The group used a bioactive lipid screen in influenza-infected human lung epithelial cells to find PD1, a derivative of omega-3 polyunsaturated fatty acid. Through this screen and subsequent experiments, the investigators determined that PD1 not only curbs influenza A virus replication, but that it could also improve the survival of mice infected with the flu virus — even those with late-stage flu infections.